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1.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(6): 1042-1047, 2019 Dec 18.
Artigo em Chinês | MEDLINE | ID: mdl-31848501

RESUMO

OBJECTIVE: To investigate the effect of clinical factors on the pathogen culture results in the patients with pyogenic spondylitis, and to find out clinical controllable factors which could increase the positive rate of the pathogen culture. METHODS: A retrospective study reviewed 40 patients who were diagnosed with pyogenic spondylitis in Peking University First Hospital from January 2011 to July 2017. The patients were divided into two groups depending on the culture results, culture negative or culture positive. The influence of clinical uncontrollable factors [the patient's age, gender, predisposing factors, infection site except spine, visual analogue score (VAS), course of disease, spinal segment, white blood cell (WBC), (neutrophilic granulocyte)% (NE%), the incidence of systemic inflammatory response syndrome (SIRS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), the incidence of paravertebral abscess] and controllable factors (prior antibiotics exposure within 2 weeks, tissue homogenate, surgical approach) on pathogen culture results were analyzed. RESULTS: Of the 40 patients, 18 patients were female and 22 patients were male. Causative germ was identified in 24/40 patients (60.00%) and dominant by gram positive cocci (68.00%). For clinical uncontrollable factors, there was no significant difference between the two groups in the patient's age, gender, predisposing factors, infection site except spine, VAS, course of disease, spinal segment, WBC, NE% and the incidence of SIRS. ESR [(94.38±6.91) mm/h, P=0.023)], CRP [(64.74±13.51) mg/L, P=0.040], and the incidence of paravertebral abscess (75%, P=0.018) in culture negative group were lower in contrast to culture positive group. For clinical controllable factors, prior antibiotics exposure within 2 weeks (P=0.058, OR=4.030, 95%CI: 0.956-16.993) and tissue homogenate (P=0.014, OR=0.171, 95%CI: 0.042-0.695) were significantly associated with the pathogen culture result. Surgical approach was not significantly associated with pathogen culture result. CONCLUSION: Patients with high level of ESR, CRP, and paravertebral abscess, would have high positive rate of pathogenic culture. Prior antibiotics exposure was associated with lower positive pathogen culture rate. Culture with tissue homogenate was more likely to find the causative germ, especially for patients without paravertebral abscess who had low level of ESR, CRP and prior antibiotics exposure.


Assuntos
Espondilite , Abscesso , Antibacterianos , Sedimentação Sanguínea , Proteína C-Reativa , Feminino , Humanos , Masculino , Estudos Retrospectivos
2.
J Dairy Sci ; 102(11): 10291-10303, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31477291

RESUMO

Maternal supply of methyl donors such as methionine (Met) during late pregnancy can affect offspring growth and development. The objective was to investigate the effect of postruminal Met supply during late pregnancy on 1-carbon, Met cycle, and transsulfuration pathways in the calf liver. During the last 28 d of pregnancy, cows were individually fed a control diet or the control diet plus rumen-protected dl-Met (MET; 0.09% dry matter intake). Liver samples obtained from calves (n = 14/group) at 4, 14, 28, and 50 d of age were used for metabolomics, real-time PCR, and enzyme activity analyses. Genes associated with 1-carbon metabolism, DNA methylation, and the cytidine 5'-diphosphocholine-choline pathway were analyzed via real-time PCR. Activity of betaine homocysteine methyltransferase, cystathionine ß-synthase, and 5-methyltetrahydrofolate homocysteine methyltransferase (MTR) was analyzed using 14C isotopes. Data were analyzed using a mixed model that included the fixed effects of maternal treatment, day, and their interaction, and the random effect was calf within maternal diet. Calves born to dams offered MET tended to have greater birth body weight and had overall greater body weight during the first 9 wk of life. However, no differences were detected for daily feed intake and average daily gain between groups. Concentrations of betaine and choline, reflecting Met cycle activity, at d 14 through 28 were greater in MET calves. Transsulfuration pathway intermediates also were altered in MET calves, with concentrations of cysteine sulfinic acid and hypotaurine (d 4 and 14) and taurine being greater (d 4, 14, 28, and 50). Despite the lack of differences in daily feed intake, the greater concentrations of the tricarboxylic acid cycle intermediates fumarate and glutamate along with NAD/NADH in MET calves indicated enhanced rates of energy metabolism. Although activity of betaine homocysteine methyltransferase was greater in MET calves at d 14, cystathionine ß-synthase was lower and increased at d 14 and 28, where it was greater compared with the control diet. Activity of MTR was lower at d 4 and 50 in MET calves. Among gene targets measured, MET calves had greater overall expression of MTR, phosphatidylethanolamine N-methyltransferase, and choline kinase α and ß. An interaction of maternal diet by time was detected for mRNA abundance of DNA methyltransferase 3α (involved in de novo methylation) due to greater values at d 4 and 14 in MET calves. Overall, the data indicate that enhanced postruminal supply of Met to cows during late pregnancy may program hepatic metabolism of the calf in the context of maintaining Met homeostasis, phosphatidylcholine and taurine synthesis, DNA methylation, and energy metabolism. These alterations potentially result in better efficiency of nutrient use, hence conferring the calf a physiologic advantage during a period of rapid growth and development. The precise biologic mechanisms remain to be established.


Assuntos
Betaína-Homocisteína S-Metiltransferase/metabolismo , Carbono/metabolismo , Bovinos/fisiologia , Metabolismo Energético , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Metionina/administração & dosagem , Animais , Animais Recém-Nascidos , Betaína/metabolismo , Betaína-Homocisteína S-Metiltransferase/genética , Biomarcadores/metabolismo , Bovinos/genética , Bovinos/crescimento & desenvolvimento , Colina/metabolismo , Dieta/veterinária , Epigênese Genética , Feminino , Fígado/enzimologia , Parto , Gravidez , Fenômenos Fisiológicos da Nutrição Pré-Natal , RNA Mensageiro/metabolismo , Rúmen/metabolismo
3.
J Dairy Sci ; 102(9): 8319-8331, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31056334

RESUMO

Although choline requirements for cows are unknown, enhanced postruminal supply may decrease liver triacylglycerol and increase flux through the Met cycle to improve immunometabolic status during a negative nutrient balance (NNB). Our objectives were to investigate the effects of postruminal choline supply during a feed restriction-induced NNB on (1) hepatic activity cystathionine ß-synthase and transcription of enzymes in the transsulfuration pathway and Met cycle; (2) hepatic metabolites in the Met cycle and the transsulfuration pathway, bile acids, and energy metabolism; and 3) plasma biomarkers of liver function, inflammation, and oxidative stress. Ten primiparous rumen-cannulated Holstein cows (158 ± 24 d postpartum) were used in a replicated 5 × 5 Latin square design with 4-d treatment periods and 10 d of recovery (14 d/period). Treatments were unrestricted intake with abomasal infusion of water, restricted intake (R; 60% of net energy for lactation requirements) with abomasal infusion of water, or R plus abomasal infusion of 6.25, 12.5, or 25 g/d choline ion. Liver tissue was collected on d 5 after infusions ended, and blood was collected on d 1, 3, and 5. Statistical contrasts were A0 versus R0 (CONT1), R versus the average of choline doses (CONT2), and tests of linear and quadratic effects of choline dose. Activity of cystathionine ß-synthase was lower with R (CONT1) and decreased linearly with choline. Hepatic glutathione was not different with R or choline, but taurine tended to be greater with choline (CONT2). Betaine and carnitine were greater with R (CONT1) and further increased with choline (CONT2). Concentrations of NAD+ were greater with choline (CONT2). Cholic and glycol-chenodeoxycholic acids were decreased by R and choline, while taurocholic and tauro-chenodeoxycholic acids were not altered. Plasma aspartate aminotransferase and bilirubin were greater with R (CONT1) but decreased with choline (CONT2). Paraoxonase was lower with R and increased with choline (CONT2). Data suggest that enhanced supply of choline during NNB decreases entry of homocysteine to the transsulfuration pathway, potentially favoring remethylation to Met by acquiring a methyl group from betaine. As such, Met may provide methyl groups for synthesis of carnitine. Along with production data indicating that 12.5 g/d choline ion improved milk yield and liver fatty acid metabolism during NNB, the changes in blood biomarkers also suggest a beneficial effect of choline supply on liver function and oxidative stress.


Assuntos
Bovinos/fisiologia , Colina/administração & dosagem , Cistationina beta-Sintase/metabolismo , Fígado/fisiologia , Metionina/metabolismo , Compostos de Enxofre/metabolismo , Abomaso/metabolismo , Animais , Betaína/metabolismo , Dieta/veterinária , Metabolismo Energético , Feminino , Humanos , Lactação/efeitos dos fármacos , Metabolismo dos Lipídeos , Fígado/efeitos dos fármacos , Leite/metabolismo , Necessidades Nutricionais , Estado Nutricional/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Período Periparto , Período Pós-Parto , Gravidez , Triglicerídeos/metabolismo
4.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(2): 321-326, 2019 Apr 18.
Artigo em Chinês | MEDLINE | ID: mdl-30996376

RESUMO

OBJECTIVE: To evaluate the effect of intrapulpal pressure simulation on the micro-tensile bond strength (µTBS) of resin cement to dentin. METHODS: Thirty extracted human third molars were selected. Occlusal enamel was removed to expose dentine surface and teeth with residual dentin thickness of 0.5-2.5 mm were selected. Dye permeation through dentin tubules with or without intrapulpal pressure (IPP) simulation, or after Single Bond Universal (SBU) application on dentin surface with IPP simulation were observed at the end of 0 min, 5 min, 30 min and 2 h. The teeth with residual dentin thickness of (1.0±0.1) mm were divided into 2 groups with IPP simulation of 15 or 0 cmH2O (1 cmH2O=0.098 kPa), which was maintained for 30 min before bonding procedure. SBU was applied on the dentin surface and light cured, then RelyX Ultimate (RLX) cement was heaped on the dentin surface (diameter=10 mm, height=4 mm) and light-cured. After the dentin-resin cement samples were stored in distilled water for 24 h at 37 °C, the samples were cut into beams with cross sectional area of 0.9 mm×0.9 mm for µTSB testing (n=100). The data were analyzed with two independent samples t-test (α=0.05). The fracture mode was observed using scanning electron microscopy (SEM). The results were analyzed with Fisher exact test (α=0.05). The rest of dentin-resin cement samples (five samples for each group) were cut perpendicular to the bonding interface and the morphology of the bonding interface was observed using SEM. RESULTS: The dye permeation through dentin tubules with IPP simulation was faster than those without IPP simulation. The µTSB of RLX to dentin with and without IPP simulation were (26.26±9.78) MPa and (28.70±9.0) MPa, respectively. The most frequent fracture mode was mixed-fracture mode. There was no significant difference between the two groups for neither bond strength nor fracture types distribution (P>0.05). Regarding the morphology of dentin-resin cement bonding interface, both groups showed 4-8 µm finger-like resin tags. CONCLUSION: With SBU pretreatment, the IPP simulation had no influence on the immediate bond strength of RLX to dentin.


Assuntos
Colagem Dentária , Cimentos de Resina , Resinas Compostas , Dentina , Adesivos Dentinários , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Resistência à Tração
5.
Beijing Da Xue Xue Bao Yi Xue Ban ; 49(2): 226-230, 2017 Apr 18.
Artigo em Chinês | MEDLINE | ID: mdl-28416829

RESUMO

OBJECTIVE: There are limited data describing the clinical characteristics and prognosis of culture negative pyogenic spondylitis. The aim of this study was to investigate the treatment, prognosis and clinical characteristics of culture negative pyogenic spondylitis. METHODS: A retrospective study reviewed 74 patients who were diagnosed with spondylitis in Peking University First Hospital from January 2010 to December 2015. A total of 27 patients suffered from pyogenic spondylitis. According to the pathogenic culture results, the patients were divided into two groups: culture negative group and culture positive group. The clinical characteristics and treatment outcomes between the two groups were compared. RESULTS: The elder were more vulnerable to pyogenic spondylitis, and of the 27 patients, 12 patients were female and 15 male. All patients had no history of administration of antibiotics prior to obtaining culture samples. A causative germ was identified in 14/27 patients (51.9%) with Staphylococcus aureus being the most common pathogen. There was no significant difference between the two groups in the patient's age, gender, visual analogue score (VAS), predisposing factor, clinical symptom, sign and spinal segment (P>0.05). Erythrocyte sedimentation rate (ESR) (P=0.056) and C-reactive protein (CRP) (P=0.040) of culture negative group were lower in contrast to culture positive group. The incidence of vertebral abscess in culture negative group was higher than in culture positive group (P=0.046). After treatment, ESR dropped almost equally in both groups, and CRP dropped faster in the culture positive group (P=0.192). At last, there was no significant difference between the two groups in hospital stay, pain relief, open debridement operation rate, and recurrence rate of infection. CONCLUSION: ESR and CRP of the culture negative patient were lower than those of the culture positive patient, and the incidence rate of paravertebral abscess was higher than that of the culture positive patient. After administration of antibiotics, there was no significant difference between the two groups in duration of antibiotics, open debridement operation rate and recurrence rate of infection. So, culture negative may not necessarily be a negative prognostic factor for pyogenic spondylitis. However, we should watch out for the drug resistant bacteria or double infection, due to the long term use of wide-spectrum antibiotic in culture negative patients.


Assuntos
Espondilite , Infecções Estafilocócicas , Staphylococcus aureus , Abscesso , Antibacterianos , Sedimentação Sanguínea , Desbridamento , Feminino , Humanos , Estudos Retrospectivos , Espondilite/diagnóstico , Espondilite/microbiologia , Espondilite/terapia , Infecções Estafilocócicas/diagnóstico , Infecções Estafilocócicas/patologia , Infecções Estafilocócicas/terapia , Resultado do Tratamento
6.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 52(4): 243-247, 2017 Apr 09.
Artigo em Chinês | MEDLINE | ID: mdl-28412791

RESUMO

Objective: To investigate surface properties of novel flowable composites after polishing and simulated brushing wear, compared to their pasty counterpart. Methods: Composites employed in this study were: three flowable composites (A1: Clearfil Majesty ES Flow; B1: Beautifil Flow Plus F00; C1: Filtek Bulk Fill) and three paste composites (A2: Clearfil Majesty; B2: Beautifil; C2: Filtek Z350. Eleven disk-shaped specimens were made for each material. The specimens were cured, then subjected to sandpaper finishing for 20 s, one-step polishing for 30 s, finally subjected to simulated brushing for 10 000 cycles. Surface roughness and glossiness were measured before finishing, after finishing, after polishing, after 5 000 brushing cycles and after 10 000 brushing cycles, respectively. Data obtained were analyzed using two-way ANOVA method. Scanning electron microscope was employed to examine the microscopic appearance of each material. Results: Surface roughness (0.11~0.22 µm) and glossiness (74.25~86.48 GU) of each material were similar after one-step polishing. After brushing simulation, roughness increased significantly and glossiness decreased significantly for each material (P<0.05). Group A1 presented the best gloss ([50.68±1.58] GU) after final wear (P<0.05). Flowable composites of group A1 and B1 tested in the present setup showed better surface properties compared to their pasty counterpart (group A2 and B2). Conclusions: Within the limit of this study, flowable composites tested in the present research can obtain similar surface polish or even better than the paste composite counterpart.


Assuntos
Resinas Compostas/química , Polimento Dentário , Escovação Dentária , Análise de Variância , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Propriedades de Superfície
7.
Genet Mol Res ; 15(1)2016 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-26909959

RESUMO

UDP-glucuronate decarboxylase (UDP-xylose synthase; UXS, EC 4.1.1.35) is an essential enzyme of the non-cellulosic polysaccharide biosynthetic pathway. In the present study, using transient expression of fluorescently labeled Gossypium hirsutum UXS (GhUXS3) protein in onion epidermal cells, we observed that this protein was distributed in the cytoplasm. The GhUXS3 cDNA of cotton was expressed in an antisense orientation in Arabidopsis thaliana by Agrobacterium tumefaciens-mediated transformation. Homozygous plants showing down-regulation of UXS were analyzed with northern blots. Compared to the untransformed control, transgenic plant showed shorter roots, earlier blossom formation, and delayed senescence. Biochemical analysis indicated that levels of rhamnose, mannose, galactose, glucose, xylose, and cellulose were reduced in some of the down-regulated antisense plants. These results suggest that GhUXS3 regulates the conversion of non-cellulosic polysaccharides and modulates their composition in plant cell walls. We also discuss a possible cellular function for GhUXS in determining the quality of cotton fibers.


Assuntos
Arabidopsis/genética , Metabolismo dos Carboidratos/genética , Carboxiliases/genética , Parede Celular/metabolismo , DNA Antissenso , Gossypium/enzimologia , Envelhecimento , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Parede Celular/química , DNA de Plantas , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Gossypium/genética , Raízes de Plantas/anatomia & histologia , Plantas Geneticamente Modificadas
8.
Geobiology ; 11(6): 593-601, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24102974

RESUMO

In this study, iron reduction and concomitant biomineralization of a deep-sea iron reducing bacterium (IRB), Shewanella piezotolerans WP3, were systematically examined at different hydrostatic pressures (0.1, 5, 20, and 50 MPa). Our results indicate that bacterial iron reduction and induced biomineralization are influenced by hydrostatic pressure. Specifically, the iron reduction rate and extent consistently decreases with the increase in hydrostatic pressure. By extrapolation, the iron reduction rate should drop to zero by ~68 MPa, which suggests a possible shut-off of enzymatic iron reduction of WP3 at this pressure. Nano-sized superparamagnetic magnetite minerals are formed under all the experimental pressures; nevertheless, even as magnetite production decreases, the crystallinity and grain size of magnetite minerals increase at higher pressure. These results imply that IRB may play an important role in iron reduction, biomineralization, and biogeochemical cycling in deep-sea environments.


Assuntos
Pressão Hidrostática , Ferro/metabolismo , Shewanella/metabolismo , China , Microscopia Eletrônica de Transmissão , Oxirredução , Água do Mar/microbiologia , Shewanella/isolamento & purificação
9.
Genet Mol Res ; 11(3): 3367-78, 2012 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-22869083

RESUMO

Sea Island cotton (Gossypium barbadense) is highly valued for its superior fiber qualities, especially fiber strength. Based on a transcript-derived fragment originated from transcriptome QTL mapping, a fiber strength related candidate gene of phosphatidylinositol 4-kinase cDNA, designated as GbPI4K, was first cloned, and its expression was characterized in the secondary cell wall thickening stage of G. barbadense fibers. The ORF of GbPI4K was found to be 1926 bp in length and encoded a predicted protein of 641 amino acid residues. The putative protein contained a clear PI3/4K kinase catalytic domain and fell into the plant type II PI4K cluster in phylogenetic analysis. In this study, the expression of cotton PI4K protein was also induced in Escherichia coli BL21 (DE3) as a fused protein. Semi-quantitative RT-PCR analysis showed that the gene expressed in the root, hypocotyl and leaf of the cotton plants. Real-time RT-PCR indicated that this gene in Sea Island cotton fibers expressed 10 days longer than that in Upland cotton fibers, and the main expression difference of PI4K between Sea Island cotton and Upland cotton in fibers was located in the secondary cell wall thickening stage of the fiber. Further analysis indicated that PI4K is a crucial factor in the ability of Rac proteins to regulate phospholipid signaling pathways.


Assuntos
1-Fosfatidilinositol 4-Quinase/genética , Mapeamento Cromossômico , Fibra de Algodão , Gossypium/enzimologia , Gossypium/genética , Locos de Características Quantitativas/genética , Transcriptoma/genética , 1-Fosfatidilinositol 4-Quinase/química , 1-Fosfatidilinositol 4-Quinase/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , DNA Complementar/genética , DNA Complementar/isolamento & purificação , Eletroforese em Gel de Poliacrilamida , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas/genética , Dados de Sequência Molecular , Especificidade de Órgãos/genética , Filogenia , Células Procarióticas/metabolismo , Estrutura Terciária de Proteína , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Especificidade da Espécie
10.
Eur J Clin Microbiol Infect Dis ; 31(11): 2943-50, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22669560

RESUMO

Aspergillus fumigatus is one of the most prominent opportunistic fungal pathogens in immunocompromised hosts. Early recognition of this infection along with prompt antifungal therapy may increase the survival rate. We expressed two potential bio-markers of A. fumigatus infection-galactomannoprotein Afmp1p and Afmp4p in Pichia pastoris. We generated 33 monoclonal antibodies (MAbs), 20 against recombinant Afmp1p (rAfmp1p) and the other 13 against recombinant Afmp4p (rAfmp4p). Subsequently, we developed two antigen-capture enzyme-linked immunosorbent assays (ELISAs) which employed MAbs as both the capture and the detection antibodies for rAfmp1p and rAfmp4p. The two antigen-capture ELISAs specifically detected Afmp1p/Afmp4p in cultures of A. fumigatus and had no cross-reaction with other tested pathogenic fungi, including Penicillium marneffei and other pathogenic Aspergillus species. The Afmp1p-captured ELISA would be positive even when the culture supernatant of A. fumigatus had been diluted to 128-fold of its original concentration. The two antigen ELISAs could capture circulating or excreted antigens during the acute phase of invasive aspergillosis (IA) in the animal model, and had no cross-reactivity to other Aspergillus-challenged animal models. We developed two antigen-capture ELISAs for the laboratory diagnosis of A. fumigatus infection. These two antigen-capture ELISAs may be useful in the clinical diagnosis of aspergillosis.


Assuntos
Anticorpos Antifúngicos , Anticorpos Monoclonais , Antígenos de Fungos/análise , Aspergilose/diagnóstico , Técnicas de Laboratório Clínico/métodos , Fungemia/diagnóstico , Glicoproteínas de Membrana/análise , Micologia/métodos , Animais , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática/métodos , Coelhos , Sensibilidade e Especificidade
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 77(3): 638-42, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20674474

RESUMO

Polycrystalline Ca(7)Mg(2)P(6)O(24):Eu(2+),Mn(2+) phosphors were prepared by a solid-state reaction under a weak reductive atmosphere. The phosphors have been characterized by X-ray diffraction and fluorescence measurements. The results show that the obtained phosphors are of single-phase rhombohedral Ca(7)Mg(2)P(6)O(24). Upon excitation of 355nm ultraviolet (UV) light, two intense broad bands have clearly been observed due to the allowed 5d-4f transition of Eu(2+) and the forbidden (4)T(1)-(6)A(1) transition of Mn(2+), respectively. A white light has been obtained from Ca(7)Mg(2)P(6)O(24):0.035Eu(2+),0.5Mn(2+) phosphor with CIE chromaticity coordinates of (x=0.32, y=0.29) and color temperature of 6175K. These results suggest that Ca(7)Mg(2)P(6)O(24):Eu(2+),Mn(2+) phosphors could be a promising candidate for UV-converting white light-emitting diodes (LEDs).


Assuntos
Európio/química , Luz , Iluminação/instrumentação , Substâncias Luminescentes/química , Manganês/química , Fosfatos/química , Cor , Cristalografia por Raios X , Transferência de Energia , Luminescência , Fosfatos/efeitos da radiação , Fotoquímica , Espectrometria de Fluorescência , Temperatura Ambiente , Raios Ultravioleta
12.
J Fluoresc ; 19(1): 105-9, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18594951

RESUMO

GdAl3(BO3)4 polycrystals co-doped with Yb3+ and Eu3+ has been synthesised by combustion method with urea. Upon the excitation at 465 nm (Eu3+/7F6-->5D2 transition), emission bands centered at 590, 613, 697 and 702 nm in the wavelength region of 550-750 nm have clearly been observed, assigned to the electronic transitions of 5D0-->7FJ (J=1, 2, 4 and 5) of Eu3+ ions, respectively. Meanwhile, an intense emission centred at 980 nm along with a shoulder at 1,040 nm has also been observed by exploiting a cross-relaxation process between the transitions of Eu3+/5D0-->7F6 and Yb3+/2F7/2-->2F5/2. On the contrary, an intense red up-conversion emission centred at 613 nm originated from the 5D0-->7F2 transition of Eu3+ has been observed upon excitation with 980 nm laser diode. The quadratic dependence of the red up-conversion intensity on the pump-laser power reveals a cooperative energy transfer mechanism from a pair of Yb3+ ions to one Eu3+ ion.


Assuntos
Boratos/síntese química , Érbio/química , Polímeros/síntese química , Itérbio/química , Boratos/química , Cristalização , Gadolínio/química , Medições Luminescentes , Polímeros/química , Difração de Pó , Sensibilidade e Especificidade , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Espectroscopia de Luz Próxima ao Infravermelho , Fatores de Tempo
13.
J Hum Evol ; 55(6): 1075-85, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18842287

RESUMO

The timing and route of the earliest dispersal from Africa to Eastern Asia are contentious topics in the study of early human evolution because Asian hominin fossil sites with precise age constraints are very limited. Here we report new high-resolution magnetostratigraphic results that place stringent age controls on excavated hominin incisors and stone tools from the Yuanmou Basin, southwest China. The hominin-bearing layer resides in a reverse polarity magnetozone just above the upper boundary of the Olduvai subchron, yielding an estimated age of 1.7Ma. The finding represents the age of the earliest documented presence of Homo, with affinities to Homo erectus, in mainland East Asia. This age estimate is roughly the same as for H. erectus in island Southeast Asia and immediately prior to the oldest archaeological evidence in northeast Asia. Mammalian fauna and pollen obtained directly from the hominin site indicate that the Yuanmou hominins lived in a varied habitat of open vegetation with patches of bushland and forest on an alluvial fan close to a lake or swamp. The age and location are consistent with a rapid southern migration route of initial hominin populations into Eastern Asia.


Assuntos
Arqueologia , Ecossistema , Fósseis , Hominidae , Magnetismo , Animais , Evolução Biológica , Dentição , Extremo Oriente , Geologia , Hominidae/anatomia & histologia , Análise de Componente Principal , Fatores de Tempo
14.
Opt Lett ; 33(16): 1816-8, 2008 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-18709097

RESUMO

The luminescence efficiency of Mn4+-doped CaAl12O19 (Mn:CAO) is significantly improved by composition modification. The leading mechanism that quenches the Mn4+ photoluminescence is the formation of Mn4+ pairs in the lattice of CaAl12O19 (CAO) with interstitial O2- for charge compensation. Mixing Mg2+ ions into the CAO lattice may form Mn4+-Mg2+ pairs and reduce the number of Mn4+ pairs, thus enhancing the Mn4+ luminescence efficiency by more than three times. It is shown that the presence of Mg2+ leads to formation of additional phases that also affect the optical properties of Mn4+.

15.
Physiol Res ; 57(3): 373-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17465691

RESUMO

We previously found that endothelin-1(1-31) (ET-1(1-31)) exhibited a pro-arrhythmogenic effect in isolated rat hearts. In this study, we further investigated the effects of ET-1(1-31) on a cell viability and observed [Ca(2+)](i) in cultured cardiomyocytes. Cultured neonatal rat cardiomyocytes were treated with 0.1, 1, and 10 nM ET-1(1-31) for 24h in the presence or absence of ET(A) receptor antagonist (BQ(123)) or phosphoramidon, a NEP/ECE inhibitor. Cell injury was evaluated by supernatant lactate dehydrogenase (LDH) assay, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content. Cell viability was assessed by MTT assay. [Ca(2+)](i) was measured with Fluo-3/AM under a laser confocal microscope. 1) ET-1(1-31) dose-dependently increased LDH release and decreased cell viability. 2) LDH and MDA levels were significantly elevated and SOD activity decreased after administration of 1 nM ET-1(1-31) for 24h, and these changes were markedly attenuated by 1 uM BQ(123). 3) Exposure to 10 nM ET 1(1-31) caused a continuous increase in [Ca(2+)](i) to cultured beating cardiomyocytes and termination of [Ca(2+)](i) transient within 6 min, and this change was reversed by 1 uM BQ(123) and attenuated by 0.5 mM phosphoramidon. These results suggest that ET-1(1-31) could cause cell injury, and that the effect of ET-1(1-31) on [Ca(2+)](i) transients is mainly mediated by ET(A) receptor and partially attributed to the conversion of ET-1(1-31) to ET-1(1-21).


Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Endotelina-1/análogos & derivados , Miócitos Cardíacos/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Animais , Animais Recém-Nascidos , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Antagonistas do Receptor de Endotelina A , Endotelina-1/farmacologia , Enzimas Conversoras de Endotelina , Glicopeptídeos/farmacologia , L-Lactato Desidrogenase/metabolismo , Malondialdeído/metabolismo , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/metabolismo , Microscopia Confocal , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/metabolismo , Peptídeos Cíclicos/farmacologia , Inibidores de Proteases/farmacologia , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina A/metabolismo , Superóxido Dismutase/metabolismo , Fatores de Tempo
16.
J Fluoresc ; 17(5): 500-4, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17609865

RESUMO

Polycrystalline GdAl(3)(BO(3))(4) phosphors co-doped with Yb(3+)/Tb(3+) and/or Nd(3+)/Yb(3+)/Tb(3+) have been synthesized by combustion method. Upon excitation with a 980 nm laser diode, an intense green upconversion luminescence has been observed in GdAl(3)(BO(3))(4):Yb,Tb phosphor. The quadratic dependence of the luminescence on the pump-laser power indicating a cooperative energy transfer process. Meanwhile, it is noticed that upon excitation with 808 nm laser diode, intense luminescence has clearly been detected in GdAl(3)(BO(3))(4):Nd,Yb,Tb phosphor. The luminescence intensity exhibits also a quadratic dependence on incident pump-laser power. However, no green-emission has been observed in GdAl(3)(BO(3))(4) phosphors co-doped with Yb(3+)/Tb(3+) or Nd(3+)/Tb(3+) respectively upon excited at 808 nm laser diode. A proposed upconversion mechanism involving energy transfer from Nd(3+) to Yb(3+), and then a cooperative energy transfer process from two excited Yb(3+) to Tb(3+) has been presented.

17.
J Fluoresc ; 17(4): 444-51, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17510779

RESUMO

This paper reports on the comparative investigation of nanocrystal structure and luminescence properties of Er(3+)/Yb(3+)-codoped gadolinium molybdate nanocrystals Gd(2)(MoO(4))(3) and Gd(2)MoO(6) synthesized by the Pechini method with citric acid and ethylene glycol. Their crystallization, structure transformation, and morphologies have been investigated by X-ray diffraction, thermogravimetric/differential scanning calorimetry, and transmission electron microscopy. It is noticed that Er(3+)/Yb(3+)-codoped monoclinic Gd(2)(MoO(4))(3) nanocrystals have shown an intense upconversion through a sintering of the organic complex precursor at 600 degrees C. Furthermore, it transforms to orthorhombic Gd(2)(MoO(4))(3) when the precursor is sintered at 900 degrees C. In counterpart of monoclinic Gd(2)MoO(6), however, the monoclinic structure remains unchanged when the precursor is sintered at a temperature ranging from 600 degrees C to 900 degrees C. Intense visible emissions of Er(3+) attributed to the transitions of (2)H(11/2), (4)S(3/2)-(4)I(15/2) at 520 and 550 nm, and (4)F(9/2)-(4)I(15/2) at 650 nm have been observed upon an excitation with a UV source and a 980 nm laser diode, and the involved mechanisms have been explained. It is quite interesting to observe obvious differences both in the excitation and the upconversion emission spectra of Er(3+)/Yb(3+)-codoped Gd(2)(MoO(4))(3) respectively with monoclinic and orthorhombic structure. The quadratic dependence of fluorescence on excitation laser power has confirmed that two-photons contribute to upconversion of the green-red emissions.

18.
Oncogene ; 26(18): 2621-34, 2007 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-17043644

RESUMO

Lung cancer is the leading cause of cancer-related deaths in the United States due, in large part, to the lack of early detection methods. Lung cancer arises from a complex series of genetic and epigenetic changes leading to uncontrolled cell growth and metastasis. Unlike genetic changes, epigenetic changes, such as DNA methylation and histone acetylation, are reversible with currently available pharmaceuticals and are early events in lung tumorigenesis detectable by non-invasive methods. In order to better understand how epigenetic changes contribute to lung cancer, and to identify new disease biomarkers, we combined pharmacologic inhibition of DNA methylation and histone deacetylation in non-small cell lung cancer (NSCLC) cell lines, with genome-wide expression profiling. Of the more than 200 genes upregulated by these treatments, three of these, neuronatin, metallothionein 3 and cystatin E/M, were frequently hypermethylated and transcriptionally downregulated in NSCLC cell lines and tumors. Interestingly, four other genes, cylindromatosis, CD9, activating transcription factor 3 and oxytocin receptor, were dominantly regulated by histone deacetylation and were also frequently downregulated in lung tumors. The majority of these genes also suppressed NSCLC growth in culture when ectopically expressed. This study therefore reveals new putative NSCLC growth regulatory genes and epigenetic disease biomarkers that may enhance early detection strategies and serve as therapeutic targets.


Assuntos
Azacitidina/farmacologia , Carcinoma Pulmonar de Células não Pequenas/genética , Metilação de DNA/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Epigênese Genética/efeitos dos fármacos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Ácidos Hidroxâmicos/farmacologia , Acetilação , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Azacitidina/análogos & derivados , Biomarcadores Tumorais , Carcinoma de Células Grandes/tratamento farmacológico , Carcinoma de Células Grandes/genética , Carcinoma de Células Grandes/patologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patologia , Imunoprecipitação da Cromatina , Ensaio de Unidades Formadoras de Colônias , Inibidores de Histona Desacetilases , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas
19.
J Neural Transm (Vienna) ; 114(5): 657-63, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17165100

RESUMO

This study aims to identify the effects of antipsychotics on plasma proteins, and on the proteins associated with schizophrenia. We applied proteomics technology to screen protein aberrations in Sprague-Dawley rats treated with antipsychotics and schizophrenic patients undergoing medication. ApoA-I was found significantly increased in the chlorpromazine-treated rats and decreased in the patients with treatment-resistant schizophrenia, which suggest that decreased levels of apoA-I might be associated with the pathology of schizophrenia and that chlorpromazine increases apoA-I levels as part of its therapeutic action.


Assuntos
Antipsicóticos/farmacologia , Apolipoproteína A-I/sangue , Química Encefálica/fisiologia , Esquizofrenia/sangue , Esquizofrenia/tratamento farmacológico , Adulto , Animais , Apolipoproteínas A/sangue , Apolipoproteínas E/sangue , Biomarcadores/análise , Biomarcadores/sangue , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/fisiopatologia , Química Encefálica/efeitos dos fármacos , Clorpromazina/farmacologia , Clozapina/farmacologia , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/fisiologia , Humanos , Masculino , Proteômica , Ratos , Ratos Sprague-Dawley , Esquizofrenia/fisiopatologia
20.
Neurosci Lett ; 394(1): 1-4, 2006 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-16378687

RESUMO

The interleukin-10 (IL-10) gene has been identified as a susceptibility gene for schizophrenia in Caucasians. A previous case-control study conducted by our group revealed a weak association between polymorphism, -592C/A, of the IL-10 gene promoter and schizophrenia. Our present study was aimed at confirming the association of the IL-10 promoter with schizophrenia using 197 Han Chinese sib-pair families. A family-based association test (FBAT) and haplotype analysis was undertaken using the FBAT v1.5.5. The global TDT was significant for a different polymorphism, -1082G/A (chi2=13.16, P=0.000285) and that the allele -1082G was preferentially transmitted to schizophrenia-affected children. Furthermore, haplotype TDT analysis showed that haplotype "GCC" was significantly associated with the disease (chi2=8.1, P=0.00443). Our results also indicate that the IL-10 gene may play a significant role in the etiology of schizophrenia among Han Chinese.


Assuntos
Saúde da Família , Predisposição Genética para Doença , Interleucina-10/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Esquizofrenia/genética , Adulto , Alelos , Distribuição de Qui-Quadrado , China/etnologia , Feminino , Frequência do Gene , Humanos , Masculino
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